Obesity is a serious health-related disorder. It has been linked as an important factor for risk of cardiovascular disease, high blood pressure, cancer, and serum cholesterol levels. Further, obesity is very resistant to treatment and often begins in childhood and tracks over time. While behavioral approaches to prevention of obesity in children is an obvious goal, the literature to date suggests that adequate treatment strategies based on informed empirical data are premature. Studies are needed both to pinpoint behavioral targets for intervention and to identify psychosocial risk factors so that obesity can be prevented safely, economically, and efficiently in children. The present study is conceptualized as a prospective combined within-subjects between subjects design. One hundred fifty children ages 3-4 will be identified as either at low risk (i.e., neither parent overweight), moderate risk (i.e., one parent overweight), or high risk (i.e., both parents overweight) for development of cardiovascular risk factors. We will carefully assess both the parents' and the child's food intake, type of food ingested, physical activity, and parent-child interactions related to food intake and physical activity. Anthropomorphic (i.e., parent/child height, weight, skinfold measures) and cardiovascular (i.e., blood pressure, heart rate) will also be collected at each observation. Subjects will be reassessed every four months for a four-year period (n=12 total observations) to assess the early natural history of cardiovascular risk factors in childhood. The outcomes of the present study will have important implications for future research. That is, the goal of this study is to pinpoint empirically based intervention targets in children so that obesity can be prevented safely and economically.